1. Field of the Invention
The present invention generally relates to a mechanism for opening and closing a cartridge compartment cover of an apparatus, and particularly relates to the mechanism, of a camera which employs a film cartridge having a light-intercepting door at a film passageway, which closes the light-intercepting door of the film cartridge in association with an opening movement of an operational member used for opening and closing the cartridge compartment cover.
2. Description of the Related Arts
Conventionally, there has been provided a camera, employing a normal film cartridge, which is so constructed that the cartridge compartment cover is prevented from being opened when a film is fed outside the film cartridge set in the cartridge compartment.
For example, the camera disclosed in Japanese Laid-Open Patent Publication No. 54-128732 has a following construction: The camera has a film rewinding spool, having a notch, which can be moved up and down by a user, a rotatable lever whose one end is pivotally supported by the camera frame and whose middle part engages with the notch of the film rewinding spool, a parallel-moving lever which is driven by the other end of the rotatable lever and which has a hook with which a pin fixed to the cartridge compartment cover engages when the cover is closed, and a magnet, whose electric switch is turned on when the film is fed outside the film cartridge and presses down the switch, for attracting one end of a safety lock lever whose other end is rotatably supported by the main frame of the camera. With this mechanism, a projection which is formed on the safety lock lever engages with a cutout made in the parallel-moving board to keep the pin of the compartment cover being locked in the hook of the parallel-moving board for preventing the cartridge compartment cover from being opened, when the film is fed out of the film cartridge with the cover being closed.
As another example, the camera disclosed in Japanese Laid-Open Patent Publication No. 55-46732 has a following construction: The camera has a film winding spool with a small-diametrical axial part which is covered by a film if the film is wound around the spool, a film detecting mechanism whose detecting member is biased by a spring to touch the periphery of the small-diametrical axial part in order to detect whether a film is wound around the film winding spool or not, a locking member, driven in association with the movement of the detecting member of the detecting mechanism, which engages with a notch formed in a film rewinding spool when the detecting member of the detecting mechanism detects no film around the film winding spool, and an operational member to operate the locking member. With this construction, if the film is fed out from the film cartridge set in the cartridge compartment and is wound around the film winding spool, the locking member engages with the notch of the film winding spool. Accordingly, even if a user operates the operational member, the film rewinding spool is prevented from being pulled out to open the compartment cover.
Meanwhile, a film cartridge having a light-intercepting door at a film passageway has been proposed as a new type of a film cartridge. An apparatus, such as a camera, employing such a film cartridge requires to be so constructed that the light-intercepting door is opened and closed when a user puts in and takes out the film cartridge with respect to the cartridge compartment. As a mechanism provided in a camera to realize this function, a mechanism for opening and closing a cartridge compartment cover, which is so constructed that a closing operation of the light-intercepting door is executed in association with the movement of an operational member of the cartridge compartment cover, has been disclosed, for example, in the U.S. Pat. No. 5,231,438.
However, if a user carelessly operates the knob for opening and closing the cartridge compartment cover when the film is outside the film case which is set inside the cartridge compartment of the camera, there exists a possibility that the film may be damaged or scarred by the light-intercepting door because of the film being sandwitched between the light-intercepting door and the film case at the film passageway, and/or that the film may be deformed so that the flatness of the film is spoiled. In case that the camera employing such a film cartridge is a normal winding type of a camera, a part of the film which may get damaged is the very part which is exposed to light upon photographing. Therefore, if the damaged part of the film is actually exposed to light, an image with a flaw would be recorded in the film, thus the quality of the image being degraded.